1. Field of the Invention
The present invention relates to hand tools, such as wrenches, and particularly to tools formed of non-metallic materials. The invention has particular application to wrenches, such as box end wrenches, of both the ratcheting and non-ratcheting type.
2. Description of the Prior Art
The present invention is an improvement of composite wrenches of the type disclosed, e.g., in U.S. Pat. No. 5,394,773 and in copending U.S. application Ser. No. 08/784,527 filed Jan. 17, 1997. Both the patent and the copending application relate to composite box end wrenches with fastener-engaging inserts, the copending application disclosing a ratcheting wrench wherein the ratchet mechanism is confined in a module, which is insert molded in the head end of the wrench body. These prior composite wrenches, which are compression molded of sheet molding compound, afford important electrically insulating, non-sparking and non-marring qualities. However, it has been found that, when such wrenches are injection molded of high-strength plastic material, they can break apart during testing to failure.
Another problem typically experienced in ratcheting box wrenches is that, during application of high torque, the torquing forces tend to try to pull the ratchet gear away from the pawl. In very high torque applications this can cause malfunction of the ratchet mechanism. This problem is alleviated by the encapsulating module utilized in the aforementioned copending application, because the module housing engages the hubs of both the pawl and the gear for holding them together. However that arrangement is relatively expensive to manufacture.